Identification Information

Citation:

Originator: Stanley A. Mertzman, Franklin and Marshall College,

Department of Earth and Environment; Richard Hazlett, Pomona College, Department of Geology;

Isaac P. Weaver, formerly at Franklin and Marshall College, Department of Earth and Environment;

Stephen Crabtree, formerly at Franklin and Marshall College, Department of Earth and Environment;

Chris Eisinger, formerly at Colorado College, Geology Department; Amy Gaffney, formerly at

Colorado College, Geology Department; Darren Gravely, formerly at Pomona College, Department

of Geology; Matthew Hall, formerly at Franklin and Marshall College, Department of Earth and

Environment; Myra Hill, formerly at Williams College, Geosciences Department; Bryan Klawiter,

formerly at Carleton College, Department of Geology; Gordon McCreight, formerly at the College

of Wooster, Department of Geology; Amber McIntosh, formerly at Colorado College, Geology

Department; Jennifer McIntosh, formerly at Whitman College, Department of Geology; Anders

Nilsson, formerly at Carleton College, Department of Geology; Stephanie Phippen, formerly at

Carleton College, Department of Geology; Sarah Robinson, formerly at Franklin and Marshall

College, Department of Earth and Environment; Jacob Sewall, formerly at Washington and Lee

University, Department of Geology; and Jeffrey Winick, formerly at Franklin and Marshall College,

Department of Earth and Environment.

Publication Date: 2009

Title:

Open-File Report O-08-08: Preliminary Geologic Map of the Mule Hill 7.5′ Quadrangle, Klamath

County, Oregon, and Siskiyou County, California

Publication Information:

Publication Place: Portland, Oregon

Publisher: Oregon Department of Geology and Mineral Industries

Description:

Abstract: This data set contains the information used to create the Preliminary Geologic Map of the Mule

Hill 7.5′ Quadrangle for Open-File Report O-08-08. This map is one of a series of geologic maps

created for quadrangles in south-central Oregon in the area of the Cascade Mountains just to the

west of Klamath Lake in Jackson and Klamath Counties (and in this case, encompassing a small

area of northern California at the Oregon and California border).

The digital raster Graphic (DRG) of the 1985 provisional edition of the U.S. Geological Survey

(USGS) 7.5′ Mule Hill quadrangle provides the base map on top of which have been placed

geospatial vector format layers of the geologic units, unit boundaries/contacts, and faults; and point

data format layers of the analyzed rock sample collection locations and volcanic centers. The geologic

units and their boundaries were determined based on a combination of observations from the field

and of hand-sample, thin-section, and geochemical analyses of 175 samples collected from within the

Mule Hill USGS 7.5′ quadrangle as well as of relevant samples collected from surrounding USGS

7.5′ quadrangles. Although the chemistry data and thin-section observations were used in creating

the map, the units are meant to be field-mappable, that is, recognizable by the study of outcrops in

the field.

The various layers (geologic units, samples, etc.) of the map were digitized in MapInfo Professional

v.7.0 from drawings on paper quadrangles, UTM coordinates, or maps from student research

reports. Rock samples were collected and analyzed by X-ray fluorescence (XRF) in 1995, 1996,

1997, 1999, 2004, and 2008. A total of 31 samples from within the Mule Hill 7.5′ quadrangle plus

several from surrounding quadrangles (but from units found in the Mule Hill quadrangle) were dated

using K-Ar or ⁴⁰Ar/³⁹Ar dating methods. The major and trace elemental chemistry data and ages are

made available in the samples table of this data set.

Purpose: These data were collected and compiled in order to better understand the local geology and

geologic history, to create a field-mappable geologic map of the U.S. Geological Survey 7.5′ Mule

Hill quadrangle to be published as Open-File Report O-08-08, and to make available the collected

chemical and age information that may be useful in various forms of study of this volcanic region. The

map is intended for a diverse audience with varying amounts of geologic understanding. This is one

of a series of geologic maps of USGS 7.5′ quadrangles in the south-central region of Oregon to be

published by the Oregon Department of Geology and Mineral Industries.

Supplemental Information: There are several different files and file formats in this data set. The geologic units

table, unit boundaries/contacts table, faults table, samples table, and volcanic centers table were

created in MapInfo Professional version 7.0 and the .TAB files can be opened using MapInfo

software. These data were later translated to ESRI compatible file formats using the MapInfo

Universal Translator extension. These translated files were then arranged and setup to properly

display the data when opened in the ESRI ArcMap software.

There is a MapInfo workspace (.WOR) file that opens the georeferenced USGS Mule Hill 7.5′

quadrangle raster image and the other Mule Hill quadrangle tables mentioned above

(MuleHill.WOR). There is also an ArcMap file (.MXD) which contains the georeferenced USGS

Mule Hill 7.5′ quadrangle and the geologic units, unit boundaries, faults, samples, and volcanic

centers shapefiles and accompanying attribute tables (MuleHill.MXD).

Time Period of Content:

Multiple Dates/Times:

Calendar Date: 1995, 1996, 1997, 1999, 2004, 2008, and 2009

Currentness Reference: ground condition and 2009 is the publication date

Status:

Progress: Complete

Maintenance and Update Frequency: Unknown

Spatial Domain:

Bounding Coordinates:

West Bounding Coordinate: -122.25

East Bounding Coordinate: -122.125

North Bounding Coordinate: 42.125

South Bounding Coordinate: 42.00

Keywords:

Theme:

Theme Keyword Thesaurus: none

Theme Keyword: geologic map

Theme Keyword: map of surface geology

Theme Keyword: surface geology

Theme Keyword: volcanoes

Theme Keyword: Oregon volcanoes

Theme Keyword: volcanic flows

Theme Keyword: lava flows

Theme Keyword: units

Theme Keyword: formations

Theme Keyword: formation boundary

Theme Keyword: contact

Theme Keyword: samples

Theme Keyword: rock samples

Theme Keyword: geochemistry

Theme Keyword: chemistry

Theme Keyword: age-dated

Theme Keyword: volcanic center

Theme Keyword: geospatial vector format

Theme Keyword: digital raster graphic

Theme Keyword: drg

Theme Keyword: topographic map

Theme Keyword: topographic quadrangle

Theme Keyword: USGS quadrangle

Theme Keyword: Open-File Report

Theme Keyword: Open-File Report 08-08

Place:

Place Keyword Thesaurus: none

Place Keyword: Oregon

Place Keyword: south-central Oregon

Place Keyword: Southern Oregon

Place Keyword: Northern California

Place Keyword: Oregon and California Border

Place Keyword: Klamath County

Place Keyword: Siskiyou County

Place Keyword: Klamath and Siskiyou Counties

Place Keyword: Oregon volcanoes

Place Keyword: Mule Hill USGS 7.5′ quadrangle

Place Keyword: Mule Hill quadrangle

Place Keyword: Mule Hill

Place Keyword: Mud Spring Mountain

Place Keyword: Klamath National Forest

Place Keyword: Klamath River

Place Keyword: Klamath Rim

Place Keyword: Hayden Creek

Place Keyword: Edge Creek

Place Keyword: Tom Creek

Place Keyword: Long Prairie Creek

Place Keyword: Camp 4 Creek

Place Keyword: Camp 4 (Site)

Place Keyword: Pokegama (Site)

Place Keyword: Potter Reservoir

Place Keyword: Ward Reservoir

Place Keyword: Griffith Reservoir

Place Keyword: Camp 4 Reservoir

Place Keyword: Tom Reservoir

Place Keyword: Cascades

Place Keyword: Cascade Mountains

Place Keyword: High Cascade volcanoes

Place Keyword: Upper Klamath Basin

Stratum:

Stratum Keyword Thesaurus: none

Stratum Keyword: surface

Stratum Keyword: surface geology

Stratum Keyword: surficial

Stratum Keyword: surficial formations

Stratum Keyword: surface formations

Stratum Keyword: surface units

Stratum Keyword: surficial units

Stratum Keyword: upper strata

Stratum Keyword: surface strata

Stratum Keyword: volcanic strata

Stratum Keyword: volcanic

Stratum Keyword: surficial volcanic deposits

Stratum Keyword: lava flows

Stratum Keyword: surficial lava flow

Stratum Keyword: Quaternary sediments

Temporal:

Temporal Keyword Thesaurus: none

Temporal Keyword: 22.8 Ma

Temporal Keyword: 22.8 million years

Temporal Keyword: present

Temporal Keyword: 22.8 million years ago to the present

Temporal Keyword: late Cenozoic

Temporal Keyword: upper Cenozoic

Temporal Keyword: Quaternary

Temporal Keyword: 23.03 Ma

Temporal Keyword: 23.03 million years

Temporal Keyword: Less than 23.03 million years

Temporal Keyword: 23.03 million years ago to the present

Temporal Keyword: Lower Miocene to Holocene

Temporal Keyword: Miocene to Holocene

Temporal Keyword: Early Miocene to Holocene

Temporal Keyword: Miocene

Temporal Keyword: Pliocene

Temporal Keyword: Tertiary

Temporal Keyword: Neogene

Temporal Keyword: Pleistocene

Temporal Keyword: Holocene

Access Constraints: none

Use Constraints: Acknowledgement of the authors and the Oregon Department of Geology and Mineral Industries

would be appreciated in products derived from these data.

Point of Contact:

Contact Person Primary: Stanley A. Mertzman

Contact Address:

Address Type: mailing and physical address

Address: Stanley A. Mertzman, Franklin and Marshall College, Department of Earth and

Environment, PO Box 3003

City: Lancaster

State or Province: Pennsylvania

Postal Code: 17604

Contact Voice Telephone: 1-717-291-3818

Contact Electronic Mail Address: stan.mertzman@fandm.edu

Contact Instructions: contact via electronic mail is preferred

Browse Graphic:

Browse Graphic File Name: MuleHillMap30x36.pdf

Browse Graphic File Description: The MuleHillMap30x36.pdf file contains the Preliminary Geologic Map of

the Mule Hill 7.5′ Quadrangle, Klamath County, Oregon, and Siskiyou County, California of Open-

File Report O-08-08. This map was made from the data provided in this data set. The basic image in

this map (the 1985 Provisional Edition USGS Mule Hill 7.5′ quadrangle overlain by the formations,

formation boundaries/contacts, faults, and sample symbols) was created in MapInfo Professional

version 7.0 using the data available in this data set (MuleHillQuadforTransparent.TAB,

MuleHillUnits.TAB, MuleHillUnitBounds.TAB, MuleHillFaults.TAB, and MuleHillSamples.TAB).

This image was exported from MapInfo Professional v. 7.0 as a Photoshop Document (.PSD) at a

zoom of 1 inch = 1.4 miles, a window size of 7.99 miles (in the export options, the actual window

size was doubled from 5.72 inches to 11.44 inches), and with a resolution of 600 pixels per inch. The

colors of the resulting .PSD file were adjusted in Adobe Photoshop CS3 to match USGS CMYK

color standards. The image was then opened in Adobe Illustrator CS3 where its size was increased

by 184.7999% to make the map scale 1:24,000. The scale was then checked manually within Adobe

Illustrator CS3 and adjusted if necessary. The samples’ map numbers, the formation labels, and the

rest of what is seen on the map, such as the time rock chart and the legend, were added to the map in

Adobe Illustrator CS3. The resulting 30 inch x 36 inch Adobe Illustrator image was saved as a

Portable Document Format (.PDF) file and the result is the image of the geologic map seen in the file

MuleHillMap30x36.pdf.

Browse Graphic File Type: PDF

Native Data Set Environment: The majority of the data files in the data set used to make the Preliminary Geologic

Map of the Mule Hill 7.5′ Quadrangle, Klamath County, Oregon, and Siskiyou County, California of Open-

File Report 08-08 was originally created using MapInfo Professional software version 7.0 running under a

Microsoft Windows 2000 Professional operating system. The data that were digitized in this environment were

the geologic units, the unit boundaries, the sample locations, and the volcanic centers layers. These files were

modified using MapInfo Professional software version 7.0 running under a Microsoft Windows XP

Professional version 2002 Service Pack 2 operating system. The USGS 7.5′ Mule Hill quadrangle digital

raster graphic (drg) was obtained from an external source (the University of Oregon Libraries website,

http://libweb.uoregon.edu/map/map_section/search.html) and was produced in a different environment.

However, in order to make a version of this USGS quadrangle drg that would make its white and green areas

transparent (so that the map could overlay the formations layer and the formations could show through) the

digital USGS quadrangle drg was modified from the state in which it was originally obtained. This modification

was done using Adobe Photoshop version 5 and the resulting image of the quadrangle was manually

georeferenced in MapInfo Professional version 7.0. The data were at times accessed and modified in MapInfo

Professional version 7.0 running under a Microsoft XP operating system. The data from the Mule Hill

quadrangle samples table have been exported from MapInfo Professional version 7.0 at least one time and

opened in Microsoft Excel for addition or modification of certain attributes, particularly chemistry data. The

Microsoft Excel file was then reopened in MapInfo Professional version 7.0. The files of this data set have

been saved and backed-up on various hard drives at various times. The most up-to-date MapInfo

Professional formatted files (DAT, ID, MAP, PSD, TAB, TFW, TIF, and WOR) have a total size of 49.1

MB.

After the data set had been produced in MapInfo Professional version 7.0, the files were converted using

MapInfo’s Universal Translator extension to produce files that could be opened with ESRI ArcMap software

version 9.2. This was done by converting the MapInfo TAB files into ESRI SHP format files. The USGS

quadrangle drg was reopened and georeferenced anew within ESRI ArcMap. Further modification of the

data files occurred within ESRI ArcMap, such as adjustment of attribute names in the attribute table,

adjustment of symbol shapes and colors, and setting of the formation regions’ colors to make these features

similar to how they appear in the MapInfo Files and on the Open-File Report geologic maps. The ESRI-

formatted files (MXD, DBF, PRJ, SBN, SBX, SHP, SHX, AUX, RRD, TFW, and TIF) have a total size of

113 MB.

Data Quality Information

Attribute Accuracy:

Attribute Accuracy Report: The attribute accuracy was tested in several ways. For sample, unit boundary,

and volcanic center location attributes (UTM coordinates), accuracy was assessed by comparison of

on-screen representations of the location (digital maps on the computer screen) to hard copy versions

(hand-drawn or similarly-demarcated locations and boundaries on top of paper USGS quadrangles).

On several occasions, the digitized versions of the Mule Hill 7.5′ quadrangle were printed out on paper

with the symbol locations and formation/unit boundaries demarcated. The print-out was then assessed

by the chief geologist of the project, Stanley A. Mertzman.

The UTM coordinates of the samples provided in the attribute table have a precision that does not

reflect that with which their locations on the map were determined. The precision reflects the values

that were assigned using MapInfo Professional version 7.0’s Coordinate Extractor extension after

manual placement (digitization) of the sample locations on the drg of the USGS 7.5′ Mule Hill

quadrangle based on comparison with the original paper quadrangles on which locations were drawn,

or in some cases, based on previously-rounded (to the nearest 10 m) UTM coordinates for samples

not shown on the original paper map(s). The accuracy of the locations drawn on the original paper

maps may vary. Prior to the year 2000, sampling locations were originally determined by use of a

Brunton compass in the field and these data were later translated to the 1:24,000 USGS 7.5′

quadrangles using plastic overlay cards marked with 1:24000 scale UTM coordinate grids or tick

marks at relevant, repeated intervals. After the year 2000, Magellan GPS units were used in the field

to determine a sample’s collection location, and again these coordinates were placed on the 1:24,000

scale USGS quadrangles using the appropriate plastic overlay card with UTM units.

The Public Land Survey System (PLSS) attributes (¼ of ¼ Section, ¼ Section, Section, Township,

and Range) in the Mule Hill samples table were created in a manner so as to be as accurate as

possible, but have not been tested for accuracy beyond the checks that occurred during their

production. The Township and Range attribute values were assigned by selection of all samples that

occurred within either manually created or downloaded polygons of the Township and Range

boundaries. Samples near a Township or Range grid line were more carefully studied on the screen to

check that the sample really did lie within the supposed Township. The Section attribute was assigned

based on a sample’s location in relation to the PLSS section grid as represented on the drg of the Mule

Hill quadrangle in MapInfo (the sections are the small quadrangles demarcated by dashed red lines

with the section numbers in their centers [where possible]).

The ¼ of ¼ Section and ¼ Section attributes were assigned for each sample based on downloaded

grids (http://www.geocommunicator.gov/GeoComm/lsis_home/home/index.shtm) which displayed the

boundaries of the ¼ of ¼ Sections and ¼ Sections of Townships. Because the Section and Township

boundaries did not always line up perfectly with those of the underlying quadrangle DRG, at times

attributes of samples close to lines in this grid had to be assigned based on mental adjustments or at

times, the use of a ruler held up to the screen, by a technician. For this reason, the accuracy of the

¼ of ¼ Section and ¼ Section attributes may be questionable in some cases, particularly in those

samples which lie close to the boundaries which demarcate these location descriptors.

The accuracy of a sample’s Unit attribute was tested by a visual check of the sample’s location in

relation to the unit boundaries as displayed in MapInfo Professional version 7.0 and by analysis of the

chemical data.

The accuracy of the chemical data is dependent on many factors not discussed here. The samples

were analyzed by X-ray fluorescence (XRF) at various times and possibly by different machines. All

that will be said is that the accuracy of the XRF chemical data is monitored and assessed during the

measurement procedure by using an instrument monitor (to account for local climate and machine

conditions on the day of measurement), by running several well-measured standards in every batch,

and by analyzing the totals counts. That the chemical attributes of each sample in the data table match

the originally assigned data from the XRF instrument was insured by copying the data from the original

Excel data files that contained the chemistry information provided by the XRF spectrometer and

pasting it into an Excel spreadsheet which eventually became the attribute table of the

MuleHillSamples.TAB MapInfo table. All of the chemical data were derived from these original Excel

files, except for those of several of the age-dated samples, which may have values copied from a

previous publication by Stanley A. Mertzman (2000). That the chemistry of the dated samples was

correctly copied into the data table was checked by comparison of the digital data to the data printed

in the publication. In cases where there were differences between the values in the original XRF results

and those in the 2000 publication (Mertzman, 2000), the values in the data table were changed to

match those of the 2000 publication.

The colors of the units are consistent between adjacent quadrangles mapped in this project and were

created as the RGB (only color mode allowed in MapInfo Professional version 7.0) equivalents of

standard USGS CMYK colors.

Logical Consistency Report: The boundaries of the Mule Hill unit polygons within the units table (MuleHillUnits

[MuleHillUnitsv2 in ESRI files]) have been checked for self- intersections, overlaps, and gaps using

MapInfo Professional version 7.0 and no self-intersections, overlaps, or gap problems were detected.

The edges of unit polygons have also been checked against those mapped in adjacent USGS 7.5′

quadrangles as part of this project, but available in other data sets (the Surveyor Mountain quadrangle to the

north [OFR O-08-03 (Mertzman, Reuer, and Schiffer, 2008)], the Parker Mountain quadrangle to the west

[unpublished at the time of writing this (02/15/09)], the Secret Spring Mountain quadrangle to the south [not

currently due to be published in this set of maps], and the Chicken Hills quadrangle to the east [unpublished at

the time of writing this (02/15/09)]). All of the boundaries were found to fit and all of the points at the

quadrangle corners were found to align perfectly (including those of units in the Spencer Creek Quadrangle to

the northeast [OFR O-08-01 (Mertzman, 2008)], the Sams Neck quadrangle to the southeast [not currently

due to be published in this set of maps], the Copco quadrangle to the southwest [not currently due to be

published in this set of maps], and the Little Chinquapin Mountain quadrangle [OFR O-08-04 (Mertzman et

al., 2008)] to the northwest). The unit boundaries polylines (from the file MuleHillUnitBounds) were drawn in a

separate layer on top of the formations/units layer using the trace function that is available in the MapInfo

Professional version 7.0 software. There are three pairs and one group of three of samples with duplicate

coordinates in the Mule Hill samples data table (MuleHillSamples) due to the collection of more than one

sample from the same location or possibly from multiple XRF analyses of different parts of the same sample.

Completeness Report: All field-mappable units (and thus unit boundaries) in the USGS 7.5′ Mule Hill quadrangle

have been mapped. At least one sample (not necessarily within the USGS Mule Hill 7.5′ quadrangle) from

each unit present in the quadrangle has been age-dated (note that the age dates of the rocks collected in the

landslide deposits (Qls) do not represent the ages of the landslides). All known faults and volcanic centers

within the Mule Hill quadrangle have been mapped and the layers containing these features have been included

in this data set. All samples known to have been collected within this quadrangle and analyzed by X-ray

fluorescence (XRF) by Professor Stanley A. Mertzman or a lab technician have been mapped and are

included within this data set. All chemistry results from the XRF analyses have been included in the attribute

table of the samples data file (MuleHillSamples). All map numbers, sample numbers, ages (applicable only to

dated samples) in millions of years (Ma), Public Land Survey System (PLSS: ¼ of ¼ Section, ¼ Section,

Section, Township, and Range according to the Willamette meridian and base line [except for samples

collected within California, which are described in relation to the Mt. Diablo meridian and base line]), UTM

coordinates (North American Datum of 1927: Zone 10), unit membership, and lithology (based on the total

alkalis versus silica [TAS] classification method for volcanic rocks described by Le Maitre [2002]) have been

included in the attribute table of the samples data file. The unit’s symbol, name, geologic time scale age, and

radiometrically-determined age(s) are the attributes of the Mule Hill units table (MuleHillUnits [MuleHillUnitsv2

in ESRI files]). The attributes of the volcanic centers table provide their UTM Easting and Northing locations

(UTM_E_m and UTM_N_m) according to the North American Datum of 1927 for the US: Zone 10 (NAD

27: Zone 10) as determined using the Coordinate Extractor extension in MapInfo Professional v. 7.0. As with

the sample location coordinates, the precision of the UTM coordinates of the volcanic centers is greater than

that with which the locations were assigned due to the precision of the results the Coordinate Extractor

produces.

Positional Accuracy:

Horizontal Positional Accuracy:

Horizontal Positional Accuracy Report: The horizontal positional accuracy of the digitized data with

regard to the original paper maps has been checked by visual comparison of the digitized

sample locations, formation boundaries, faults, and volcanic centers to the original paper maps

when possible. The positional accuracy of the original sample locations on the original paper

maps may vary depending on the location-determining methods used as discussed above

(Brunton compass or Magellan GPS after the year 2000). The positions of the unit boundaries

are approximate and their accuracy has not necessarily been field tested. Analysis of the

collected samples (chemistry, hand-sample, and thin sections) and familiarity with the area

from lots of time spent in the field by experienced geologists ought to ensure reasonable

accuracy of the mapped unit boundaries, although this is not quantifiable.

Lineage:

Source Information:

Source Citation:

Originator: U.S. Geological Survey

Publication Date: 1985

Title: Mule Hill Quadrangle: Oregon–California 7.5 Minute Series (Topographic)

Edition: Provisional Edition 1985

Geospatial Data Presentation Form: map and raster digital data (digital raster graphic [drg])

of map

Series Information:

Series Name: U.S. Geological Survey 7.5 Minute Series Topographic Quadrangles

Series Issue: Mule Hill, Oreg.— Calif.: Provisional Edition 1985: 42122-A2-TF-024

Publication Information:

Publication Place: Denver, CO or Reston, VA

Publisher: U.S. Geological Survey

Other Citation Details: A drg of this map can be downloaded from the University of Oregon

Libraries website.

Online Linkage: UO Libraries website:

http://libweb.uoregon.edu/dc/24k_lookup/displaymap.php?ohio_code=42122a2

Source Scale Denominator: 24,000

Type of Source Media: Paper and Online

Source Time Period of Content:

Time Period Information:

Multiple Dates/Times:

Calendar Dates: 1980, 1981, 1985

Source Currentness Reference: 1980 corresponds to the year in which aerial photographs

were taken; the map was field checked in 1981; and the map was edited and

published in 1985. The year of production of the particular drg used in the data set is

not currently known.

Source Citation Abbreviation: 42122a2

Source Contribution: The USGS Mule Hill 7.5 minute paper quadrangle was used as the base

map on which the geology of the quadrangle was mapped by Stanley A. Mertzman

and students (the exact version(s) of the map(s) used as the original base maps is not

currently known). A downloaded drg of the Mule Hill 7.5 minute quadrangle

(42122a2) was used as the base map for this data set onto which the sample

locations, units, faults, and volcanic centers were copied (digitized) from a paper

version (or versions) of the map(s) produced by the geologists involved in this project.

It is also possible that the sample collection locations came from UTM coordinates

provided in a report by one of the geologists.

Process Step:

Process Description: The first step in the production of this data set was the collection of rock

samples and observations from the field. The samples’ chemistries were determined by X-ray

fluorescence (XRF) spectroscopy (see http://fandm.edu/x7985.xml for an overview of the

XRF spectroscopy preparation and analysis procedure). The hand-samples were carefully

analyzed and described. Thin sections of the rocks allowed further description of certain

samples by analysis with a petrographic microscope.

A sample’s collection location was determined in the field using a Brunton compass prior to

2000, and with a Magellan GPS unit after 2000. The sample locations were marked on paper

versions of the USGS 7.5′ Mule Hill quadrangle. These locations were digitized using a

georeferenced (to the North American Datum of 1927 [NAD 27] zone 10 horizontal datum)

drg of the quadrangle in MapInfo Professional version 7.0 by placing a point (node) in a layer

above the drg at the location identical to the sample’s location on the paper map. If a sample

was not present on a map, but the UTM coordinates of its collection location were known,

these coordinate values were used to plot the sample’s collection location in MapInfo. This

process was the first step in the production of the Mule Hill samples table (MuleHillSamples);

it produced point data from which the UTM coordinates, if not already known, could be

extracted to the attribute table. Please note that the precision of the UTM coordinates does

not necessarily reflect the precision with which they were originally obtained, but represents

the precision obtained when extracting the coordinates of the points (with MapInfo

Professional version 7.0’s coordinate extractor tool) after they were digitized from the paper

maps.

The MuleHillSamples attribute table was exported from MapInfo Professional v. 7.0 at least

one time to Microsoft Excel, where other sample attributes were added and or modified (such

as lithology and chemistry data). These Excel spreadsheets were then imported back into

MapInfo Professional version 7.0 and the previously extracted UTM coordinates were used

to re-plot the sample locations over the 7.5′ quadrangle drg. The drg of the quadrangle was

also used in assigning some of the Township, Range, and Section attributes to the samples.

Downloaded PLSS grids also aided in assigning these and other PLSS attributes (¼ of ¼

section, ¼ section) to the samples table.

The combination of the analyses of collected samples and a familiarity with the area from a lot

of time spent in the field allowed Stanley A. Mertzman to determine and discriminate between

the units present within the Mule Hill 7.5′ quadrangle and to draw the approximate locations

of their boundaries on the paper USGS 7.5′ topographic maps. These boundaries were then

digitized in the same manner as sample locations, by copying their locations from on the paper

map to a MapInfo layer on top of a drg of the same map (USGS 7.5′ Mule Hill quadrangle

(42122a2)). This was done using the polygon tool in MapInfo Professional version 7.0. The

boundary of the unit on the map (contact) (MuleHillUnitBounds MapInfo Table) was digitized

as the boundary of the polygon in MapInfo. The unit polygons were colored based on RGB

equivalents of standard USGS CMYK colors. The unit ages, names, and symbols

(abbreviated names) were added to the attribute table at a later stage of the process. It was

decided that a separate layer (file) should be made for the unit boundaries (contacts) within

the quadrangle because the edges of the unit polygons did not necessarily correspond to the

actual unit boundaries. The edges of the unit polygons were limited by the quadrangle

boundaries, so although many units extend beyond the boundaries of the Mule Hill USGS

7.5′ quadrangle, the polygons for this data set were limited to the area of the quadrangle.

In order to make a layer (MuleHillUnitBounds) that corresponded to the actual unit

boundaries (ground-surface contacts between two rock units), the true unit boundaries (not

those cut off at the quadrangle’s edges) were made by tracing (using MapInfo’s trace

function) all of the unit polygons’ edges, except those that corresponded with the 4 sides of

the quadrangle. This process created the polylines that now represent the unit

boundaries/contacts in this data set (MuleHillUnitBounds).

The volcanic centers’ locations were originally determined from field observations and sample

analyses. Their locations were marked on a paper version of the quadrangle with temporary

stickers and then digitized by copying the location to the identical spot on the drg of the

quadrangle. The UTM coordinates of these locations have been extracted into the volcanic

centers attribute table using MapInfo version 7.0’s Coordinate Extractor tool. Please note

that, like the precision of the samples’ UTM coordinates, the precision of the volcanic centers

UTM coordinates does not reflect that with which the location was determined, but is the

result of using MapInfo v. 7.0’s Coordinate Extractor Extension that outputs the data in a

certain format.

There is one fault in the Mule Hill quadrangle. The fault’s location was primarily determined

based on field observations, but in certain locations may be inferred based on the local

topography and geology combined with the consideration of the location of faults that went to

the edge of adjacent 7.5 minute Chicken Hills USGS quadrangle. The fault polyline is found in

the MuleHillsFaults.TAB file.

After the creation of final forms of all of the necessary files in MapInfo, the MapInfo Universal

Translator Extension was used to convert the MapInfo-formatted data set to ESRI-format

files. This involved converting the mapinfo TAB files of the unit polygons, unit boundary

(contact) polylines, sample points, fault polyline, and volcanic center points to shapefiles

(SHPs). These files were opened and adjusted in ESRI ArcMap version 9.2. It should be

noted that two additional fields (attributes) were created when the MapInfo TAB files were

converted to ESRI-format files. These two fields are the “FID” and the “Shape*.” The “FID”

numbers all of the objects in the data tables and the “Shape*” attribute tells what kind of data

an object is (multipoint, polyline, polygon). These added fields are not discussed with the rest

of the attributes below. It should also be noted that certain attribute names of the ESRI-format

files were changed by the program during their creation and were not able to be modified by

the technician. In such cases, the alias of the attribute was changed to fit the original attribute

titles (as shown below), but the names had to be left as they were converted.

The digital versions of the sample collection locations; units and unit boundaries; the fault; and

the volcanic centers locations were checked by visual comparison of the digital data on the

computer screen (in MapInfo) or on printed copies to the original source paper maps.

Furthermore, final printed or digital (PDF) versions of the resulting map(s) were assessed by the

chief geologist of this project, Stanley A. Mertzman.

Source Used Citation Abbreviation: 42122a2

Process Date: 2009

Process Contact:

Contact Information:

Contact Person Primary:

Contact Person: Isaac Weaver

Contact Position: Research Assistant

Contact Address:

Address Type: mailing and physical address

Address: Isaac Weaver, Franklin and Marshall College, Department of Earth

and Environment, PO Box 3003

City: Lancaster

State or Province: Pennsylvania

Postal Code: 17604

Contact Voice Telephone: Unavailable

Contact Electronic Mail Address:

isaacweaver@hotmail.com

Spatial Data Organization Information

Indirect Spatial Reference: This data set contains the drg of the USGS 7.5′ Mule Hill quadrangle and files

with point data locations at which rock samples were collected from outcrops, polygons of the

geologic units, polylines of the unit boundaries (contacts), a polyline of the fault, and point data

volcanic center locations for the U.S. Geological Survey 7.5 minute Mule Hill quadrangle.

Direct Spatial Reference Method: Point, Vector, and Raster

Spatial Reference Information

Horizontal Coordinate System Definition:

Planar:

Grid Coordinate System:

Grid Coordinate System Name: Universal Transverse Mercator

Universal Transverse Mercator:

UTM Zone Number: 10

Transverse Mercator:

Scale Factor at Central Meridian: 0.999600

Longitude of Central Meridian: -123.000000

Latitude of Projection Origin: 0.000000

False Easting: 500000.000000

False Northing: 0.000000

Planar Coordinate Information:

Planar Coordinate Encoding Method: coordinate pair

Coordinate Representation:

Abscissa Resolution: 0.01

Ordinate Resolution: 0.01

Planar Distance Units: meters

Geodetic Model:

Horizontal Datum Name: North American Datum of 1927

Ellipsoid Name: Clarke 1866

Semi-major Axis: 6378206.4

Denominator of Flattening Ratio: 294.9787

Entity and Attribute Information

Detailed Description:

Entity Type:

Entity Type Label: Unit

Entity Type Definition: A rock unit (or simply unit), with regard to this data set, is a body of rock with

a limited range of lithological characteristics (as determined by analyses of outcrops and

samples in the field and in the laboratory) that can be distinguished from other bodies of rocks

by observations made in the field (such as analysis of outcrops or hand-samples collected from

them). That is to say, a unit is field-mappable according to the definition used in the creation of

this data set. Nevertheless, the chemistry data and other observations not possible in the field

were still considered in determining and discriminating the units. In the Mule Hill 7.5′

quadrangle, a unit may represent one or more volcanic flows, vent deposits, or quaternary

landslide deposits. A unit has an age (or age-range), which has been determined by

radiometric dating of collected samples (except for the Quaternary landslide deposits [Qls],

although samples were collected within the Qls area, these should be considered as float

material). It should be noted that the vent deposit unit (Tbv) could perhaps best described as

a sub-unit of the unit in which it is found (Basalt of Sheepy Creek [Tpbsc]), but is classified

separately due to the difference in lithology.

Detailed descriptions of the units found within the USGS 7.5′ Mule Hill quadrangle are found

in the Open-File Report O-08-08 (Mertzman et al., 2008). In this data set, the units are

found in the MuleHillUnits (MuleHillUnitsv2 in ESRI files) file and are colored polygons with

their edges placed at the approximate locations of the contacts, except when limited by the

quadrangle boundaries.

Entity Type Definition Source: See Mertzman et al. (2008) for detailed descriptions of the units found

within the Mule Hill quadrangle.

Attribute:

Attribute Label: Symbol

Attribute Definition: The symbol is a form of shorthand text, specific to a unit, that is created by

combining age and lithology information with an abbreviated form of the unit’s name. The

symbol attribute is meant to be displayed on the pdf versions of the geologic map to save

space while identifying the unit, or it can be displayed when viewing the data in MapInfo or

ArcMap on a computer. It is intended that the symbol convey age, lithology, and unit name

information. The first letter is capitalized and represents the period-age of the formation

(T=Tertiary and Q=Quaternary). If the first letter of the symbol is a capital T, then the second

letter represents the epoch-age of the formation (p=Pliocene and m=Miocene). It should be

noted that these first two letters only represent the oldest dated age of the formation.

Therefore, a unit’s age may span from period to period or epoch to epoch, but this cannot be

discerned from the symbol. The remaining letters in the symbol indicate the lithology of the

formation and its name. The lithology (for volcanic units, b=basalt, ba= basaltic andesite, and

a=andesite) comes first after the age information in the abbreviation of the unit’s name, which

is usually based on an outstanding geographic or topographic feature present in the area of the

unit. The vent deposit and the Quaternary sedimentary unit do not follow this pattern, are

treated more generally, and only have the age information followed by a general lithology

abbreviation because these units and sub-units (vent deposits) do not have specific names

based on a geographic feature.

Attribute Definition Source: None

Attribute Domain Values:

Enumerated Domain:

Enumerated Domain Value: Qls

Enumerated Domain Value Definition: Landslide deposits (Pleistocene to Holocene).

Enumerated Domain Value Definition Source: Open-File Report O-08-08

(Mertzman et al., 2008).

Enumerated Domain:

Enumerated Domain Value: Tbv

Enumerated Domain Value Definition: Basaltic to basaltic andesite vent deposits

(Pliocene). This unit should be considered a sub-unit of the unit in which it is

found. Tbv is present in only one unit on this map, the Basalt of Sheepy Creek

(Tpbsc).

Enumerated Domain Value Definition Source: Open-File Report O-08-08

(Mertzman et al., 2008).

Enumerated Domain:

Enumerated Domain Value: Tpblp

Enumerated Domain Value Definition: Basalt of Long Prairie (Middle Pliocene to

Lower Pleistocene).

Enumerated Domain Value Definition Source: Open-File Report O-08-08

(Mertzman et al., 2008).

Enumerated Domain:

Enumerated Domain Value: Tpbapm

Enumerated Domain Value Definition: Basaltic Andesite of Parker Mountain (Middle

Pliocene to Lower Pleistocene).

Enumerated Domain Value Definition Source: Open-File Report O-08-08

(Mertzman et al., 2008).

Enumerated Domain:

Enumerated Domain Value: Tpbms

Enumerated Domain Value Definition: Basalt of Mud Spring Mountain (Middle to

Upper Pliocene).

Enumerated Domain Value Definition Source: Open-File Report O-08-08

(Mertzman et al., 2008).

Enumerated Domain:

Enumerated Domain Value: Tpbsc

Enumerated Domain Value Definition: Basalt of Sheepy Creek (Middle to Upper

Pliocene).

Enumerated Domain Value Definition Source: Open-File Report O-08-08

(Mertzman et al., 2008).

Enumerated Domain:

Enumerated Domain Value: Tpbab

Enumerated Domain Value Definition: Basaltic Andesite of Buck Mountain (Middle

Pliocene).

Enumerated Domain Value Definition Source: Open-File Report O-08-08

(Mertzman et al., 2008).

Enumerated Domain:

Enumerated Domain Value: Tpbtr

Enumerated Domain Value Definition: Basalt of Tom Reservoir (Lower to Upper

Pliocene).

Enumerated Domain Value Definition Source: Open-File Report O-08-08

(Mertzman et al., 2008).

Enumerated Domain:

Enumerated Domain Value: Tpbgb

Enumerated Domain Value Definition: Basalt of Grouse Butte (Lower to Middle

Pliocene).

Enumerated Domain Value Definition Source: Open-File Report O-08-08

(Mertzman et al., 2008).

Enumerated Domain:

Enumerated Domain Value: Tpbah

Enumerated Domain Value Definition: Basaltic Andesite of Hayden Mountain

(Lower to Middle Pliocene).

Enumerated Domain Value Definition Source: Open-File Report O-08-08

(Mertzman et al., 2008).

Enumerated Domain:

Enumerated Domain Value: Tpbac

Enumerated Domain Value Definition: Basaltic Andesite of Camp Creek

(Lower to Middle Pliocene).

Enumerated Domain Value Definition Source: Open-File Report O-08-08

(Mertzman et al., 2008).

Enumerated Domain:

Enumerated Domain Value: Tmbam

Enumerated Domain Value Definition: Basaltic Andesite of Mule Hill (Upper

Miocene to Lower Pliocene).

Enumerated Domain Value Definition Source: Open-File Report O-08-08

(Mertzman et al., 2008).

Enumerated Domain:

Enumerated Domain Value: Tmbgm

Enumerated Domain Value Definition: Basalt of Grizzly Mountain (Upper Miocene).

Enumerated Domain Value Definition Source: Open-File Report O-08-08

(Mertzman et al., 2008).

Enumerated Domain:

Enumerated Domain Value: Tmbkr

Enumerated Domain Value Definition: Basalt of the Klamath Rim (Upper Miocene).

Enumerated Domain Value Definition Source: Open-File Report O-08-08

(Mertzman et al., 2008).

Enumerated Domain:

Enumerated Domain Value: Tmbhc

Enumerated Domain Value Definition: Basalt to Andesite of Hayden Creek (Middle

Miocene).

Enumerated Domain Value Definition Source: Open-File Report O-08-08

(Mertzman et al., 2008).

Enumerated Domain:

Enumerated Domain Value: Tmvhf

Enumerated Domain Value Definition: Heppsie Formation (Lower Miocene).

Enumerated Domain Value Definition Source: Open-File Report O-08-08

(Mertzman et al., 2008).

Attribute:

Attribute Label: Name

Attribute Definition: The Name attribute represents the name of the unit of which the entity is a part.

The name combines information on the lithology of the unit with a geographic feature located

within or near the unit’s boundary, such as a mountain or a body of water. Detailed

descriptions of the units found within the Mule Hill USGS 7.5′ quadrangle are available in

Open-File Report O-08-08 (Mertzman et al., 2008).

Attribute Definition Source: See Mertzman et al., 2008.

Attribute Domain Values:

Enumerated Domain:

Enumerated Domain Value: Landslide deposits

Enumerated Domain Value Definition: See Open-File Report O-08-08 (Mertzman et

al., 2008) for a detailed description of this unit.

Enumerated Domain Value Definition Source: Open-File Report O-08-08

(Mertzman et al., 2008).

Enumerated Domain:

Enumerated Domain Value: Basaltic to basaltic andesite vent deposits

Enumerated Domain Value Definition: Poorly lithified to unconsolidated lapilli to ash-

sized cinders black to brown to red with lesser amounts of similarly colored

lava spatter, bombs, and scoria. These deposits mark volcanic vents areas

that are often cinder cones. Pliocene in age.

These areas should be considered sub-units of the units in which they are

found and samples found within areas of basaltic to basaltic andesite vent

deposits are classified as part of the complimentary unit.

Enumerated Domain Value Definition Source: Open-File Report O-08-08

(Mertzman et al., 2008).

Enumerated Domain:

Enumerated Domain Value: Basalt of Long Prairie

Enumerated Domain Value Definition: See Open-File Report O-08-08

(Mertzman et al., 2008) for a detailed description of this unit.

Enumerated Domain Value Definition Source: Open-File Report O-08-08

(Mertzman et al., 2008).

Enumerated Domain:

Enumerated Domain Value: Basaltic Andesite of Parker Mountain

Enumerated Domain Value Definition: See Open-File Report O-08-08

(Mertzman et al., 2008) for a detailed description of this unit.

Enumerated Domain Value Definition Source: Open-File Report O-08-08

(Mertzman et al., 2008).

Enumerated Domain:

Enumerated Domain Value: Basalt of Mud Spring Mountain

Enumerated Domain Value Definition: See Open-File Report O-08-08

(Mertzman et al., 2008) for a detailed description of this unit.

Enumerated Domain Value Definition Source: Open-File Report O-08-08

(Mertzman et al., 2008).

Enumerated Domain:

Enumerated Domain Value: Basalt of Sheepy Creek

Enumerated Domain Value Definition: See Open-File Report O-08-08 (Mertzman

et al., 2008) for a detailed description of this unit.

Enumerated Domain Value Definition Source: Open-File Report O-08-08

(Mertzman et al., 2008).

Enumerated Domain:

Enumerated Domain Value: Basaltic Andesite of Buck Mountain

Enumerated Domain Value Definition: See Open-File Report O-08-08 (Mertzman

et al., 2008) for a detailed description of this unit.

Enumerated Domain Value Definition Source: Open-File Report O-08-08

(Mertzman et al., 2008).

Enumerated Domain:

Enumerated Domain Value: Basalt of Tom Reservoir

Enumerated Domain Value Definition: See Open-File Report O-08-08

(Mertzman et al., 2008) for a detailed description of this unit.

Enumerated Domain Value Definition Source: Open-File Report O-08-08

(Mertzman et al., 2008).

Enumerated Domain:

Enumerated Domain Value: Basalt of Grouse Butte

Enumerated Domain Value Definition: See Open-File Report O-08-08 (Mertzman

et al., 2008) for a detailed description of this unit.

Enumerated Domain Value Definition Source: Open-File Report O-08-08

(Mertzman et al., 2008).

Enumerated Domain:

Enumerated Domain Value: Basaltic Andesite of Hayden Mountain

Enumerated Domain Value Definition: See Open-File Report O-08-08 (Mertzman

et al., 2008) for a detailed description of this unit.

Enumerated Domain Value Definition Source: Open-File Report O-08-08

(Mertzman et al., 2008).

Enumerated Domain:

Enumerated Domain Value: Basaltic Andesite of Camp Creek

Enumerated Domain Value Definition: See Open-File Report O-08-08 (Mertzman

et al., 2008) for a detailed description of this unit.

Enumerated Domain Value Definition Source: Open-File Report O-08-08

(Mertzman et al., 2008).

Enumerated Domain:

Enumerated Domain Value: Basaltic Andesite of Mule Hill

Enumerated Domain Value Definition: See Open-File Report O-08-08 (Mertzman

et al., 2008) for a detailed description of this unit.

Enumerated Domain Value Definition Source: Open-File Report O-08-08

(Mertzman et al., 2008).

Enumerated Domain:

Enumerated Domain Value: Basalt of Grizzly Mountain

Enumerated Domain Value Definition: See Open-File Report O-08-08 (Mertzman

et al., 2008) for a detailed description of this unit.

Enumerated Domain Value Definition Source: Open-File Report O-08-08

(Mertzman et al., 2008).

Enumerated Domain:

Enumerated Domain Value: Basalt of the Klamath Rim

Enumerated Domain Value Definition: See Open-File Report O-08-08 (Mertzman

et al., 2008) for a detailed description of this unit.

Enumerated Domain Value Definition Source: Open-File Report O-08-08

(Mertzman et al., 2008).

Enumerated Domain:

Enumerated Domain Value: Basalt to Andesite of Hayden Creek

Enumerated Domain Value Definition: See Open-File Report O-08-08 (Mertzman

et al., 2008) for a detailed description of this unit.

Enumerated Domain Value Definition Source: Open-File Report O-08-08

(Mertzman et al., 2008).

Enumerated Domain:

Enumerated Domain Value: Heppsie Formation

Enumerated Domain Value Definition: See Open-File Report O-08-08 (Mertzman

et al., 2008) for a detailed description of this unit.

Enumerated Domain Value Definition Source: Open-File Report O-08-08

(Mertzman et al., 2008).

Attribute:

Attribute Label: Age_Geologic_Time_Scale

Attribute Definition: The Age_Geologic_Time_Scale represents the age of a unit in terms of the

“Stage Age” (convention not completely followed, only Lower, Middle, and Upper are used

as classes in this naming category) and “Series Epoch” classifiers of the 2007 International

Stratigraphic Chart (International Commission on Stratigraphy, 2007) as defined by dates

calculated by Gradstein et al. (2004). The attribute value was determined by a comparison

of a unit’s dated age(s) to the stratigraphic age boundaries in the 2007 International

Stratigraphic Chart (International Commission on Stratigraphy, 2007). A range of geologic

time scale ages may be provided for a unit due to a range of ages calculated for one or more

samples therein by K-Ar or ⁴⁰Ar/³⁹Ar dating methods. This attribute provides a low resolution

representation of the age of a unit.

Attribute Definition Source: See Open-File Report O-08-08 (Mertzman et al., 2008), International

Convention on Stratigraphy (2007), and Gradstein et al. (2004).

Attribute Domain Values:

Enumerated Domain:

Enumerated Domain Value: Pleistocene to Holocene

Enumerated Domain Value Definition: Unknown Pleistocene to Holocene

(<1.806 Ma).

Enumerated Domain Value Definition Source: Gradstein et al. (2004), International

Convention on Stratigraphy (2007), and Open-File Report O-08-08

(Mertzman et al., 2008).

Enumerated Domain:

Enumerated Domain Value: Pliocene

Enumerated Domain Value Definition: 5.332 – 1.806 million years ago (Ma)

Enumerated Domain Value Definition Source: Gradstein et al. (2004), International

Convention on Stratigraphy (2007), and Open-File Report O-08-08

(Mertzman et al., 2008).

Enumerated Domain:

Enumerated Domain Value: Lower Pleistocene

Enumerated Domain Value Definition: 1.806 – 0.781 million years ago (Ma)

Enumerated Domain Value Definition Source: Gradstein et al. (2004), International

Convention on Stratigraphy (2007), and Open-File Report O-08-08

(Mertzman et al., 2008).

Enumerated Domain:

Enumerated Domain Value: Middle Pliocene

Enumerated Domain Value Definition: 3.600 – 2.588 million years ago (Ma).

Enumerated Domain Value Definition Source: Gradstein et al. (2004), International

Convention on Stratigraphy (2007), and Open-File Report O-08-08

(Mertzman et al., 2008).

Enumerated Domain:

Enumerated Domain Value: Upper Pliocene

Enumerated Domain Value Definition: 2.588 – 1.806 million years ago (Ma)

Enumerated Domain Value Definition Source: Gradstein et al. (2004), International

Convention on Stratigraphy (2007), and Open-File Report O-08-08

(Mertzman et al., 2008).

Enumerated Domain:

Enumerated Domain Value: Lower Pliocene

Enumerated Domain Value Definition: 5.332 – 3.600 million years ago (Ma)

Enumerated Domain Value Definition Source: Gradstein et al. (2004), International

Convention on Stratigraphy (2007), and Open-File Report O-08-08

(Mertzman et al., 2008).

Enumerated Domain:

Enumerated Domain Value: Upper Miocene

Enumerated Domain Value Definition: 11.608 – 5.332 million years ago (Ma)

Enumerated Domain Value Definition Source: Gradstein et al. (2004), International

Convention on Stratigraphy (2007), and Open-File Report O-08-08

(Mertzman et al., 2008).

Enumerated Domain:

Enumerated Domain Value: Lower Miocene

Enumerated Domain Value Definition: 23.03 – 15.97 million years ago (Ma)

Enumerated Domain Value Definition Source: Gradstein et al. (2004), International

Convention on Stratigraphy (2007), and Open-File Report O-08-08

(Mertzman et al., 2008).

Attribute:

Attribute Label: Age_Ma

Attribute Definition: The Age_Ma attribute describes the absolute age or age-range of a unit in

millions of years as determined by the dating of collected rock samples with K-Ar or

⁴⁰Ar/³⁹Ar methods. The values are presented with the calculated ages and their error ranges.

All units have been age-dated using either of the two aforementioned radiometric dating

methods, except for the Qls (Landslide Deposits) unit, although float samples within the Qls

have been radiometrically dated. The Range domain described below pertains to the

radiometrically dated samples. The value for the Qls unit is “unknown Pleist. To Hol.

(<1.806 Ma).” The Tbv unit (sub-unit) of the Tpbsc unit is tentatively given the age of which

it is considered part since an age-dated sample did not come from this area; therefore, a

question mark is displayed with this Tbv area’s age values to imply its tentative nature.

Attribute Definition Source: See Mertzman et al. (2008).

Attribute Domain Values:

Range Domain:

Range Domain Minimum: <1.806 Ma

Range Domain Maximum: 22.77 +/- 0.13 Ma

Attribute Units of Measure: Millions of years (Ma)

Detailed Description:

Entity Type:

Entity Type Label: Contact/Unit Boundary

Entity Type Definition: A unit boundary is the same as a

contact. It is the ground-surface (or its trace on the surface, if buried/concealed) boundary

between two rock units. In this data set, the unit boundaries are polylines traced on the unit

polygon boundaries (except on the boundaries that corresponded with the edges of the

quadrangle and were not the true unit boundaries). The contacts have been approximately

located. The contacts between the Heppsie Formation (Tmvhf) and the other volcanic units

are inferred, and are represented as dashed lines. The unit boundaries are contained in the

MuleHillUnitBounds file.

Entity Type Definition Source: None

Attribute:

Attribute Label: Approximate_or_Inferred

Attribute Definition: Attribute Definition: This attribute indicates

whether a contact is visible on the Earth’s surface (approximately located) or inferred (buried

and difficult to locate on the Earth’s surface). The inferred boundaries exist between the

Heppsie Formation (Tmvhf) and the other volcanic units due to the friable nature of the

Tmvhf. The inferred contacts/unit boundaries are displayed as dashed lines, the approximately

located contacts are solid lines.

Attribute Definition Source: None

Attribute Domain Values:

Enumerated Domain:

Enumerated Domain Value: Approximate

Enumerated Domain Value Definition: These contacts/unit boundaries are

evident on the surface of the Earth, and their locations on the map are

approximate.

Enumerated Domain Value Definition Source: None

Enumerated Domain:

Enumerated Domain Value: Inferred

Enumerated Domain Value Definition: These contacts/unit boundaries are buried or

otherwise not evident on the Earth’s surface and their locations have been

inferred. On the Mule Hill 7.5 minute quadrangle, the inferred contacts exist

between the Tmvhf and other volcanic units due to the friable nature of the

Tmvhf.

Enumerated Domain Value Definition Source: None

Detailed Description:

Entity Type:

Entity Type Label: Sample

Entity Type Definition: A sample, with regard to this data set, is a field-collected rock specimen from

an in situ outcrop (lava flows or vent deposits) – or in the case of the samples from the Qls

areas, a piece of float – located within the boundaries of the Mule Hill USGS 7.5′ quadrangle

(42122a2). The goal was to collect a representative suite of samples for each unit. A sample

may have been apportioned for the following possible types of analysis: hand-sample analysis

with possible use of a hand lens and other tools; heating to measure the loss on ignition (LOI);

chemical analysis by X-ray fluorescence (XRF) spectroscopy (all samples); thin section

analysis; age-dating by either K-Ar or ⁴⁰Ar/³⁹Ar methods. Samples can be displayed as point

data.

In the MuleHillSamples file, sample collection locations are indicated with either a black

triangle or with a yellow square with a black outline. The black triangles represent samples for

which there is available chemistry data in the attributes table. The yellow squares represent

samples that have been age-dated by K-Ar or ⁴⁰Ar/³⁹Ar dating methods and also have

chemistry data in the data table (attribute table).

Entity Type Definition Source: See Mertzman et al. (2008).

Attribute:

Attribute Label: Map_No

Attribute Definition: The Map_No is the map number. The map number is displayed on the geologic

maps made using this dataset, such as the MuleHillMap30x36.pdf discussed above. Map

numbers were assigned sequentially to all of the samples after they were organized by age,

formation, and silica content. The samples and their data were organized first by the formation,

from oldest to youngest formation. Within each formation the data were further organized by

placing age-dated samples before samples that were not age-dated. The age-dated samples

for each formation were arranged by silica content, from lowest to highest silica content. Then

the non-age-dated samples for each formation were arranged by silica content, from lowest to

highest. After the data were organized, the map numbers were assigned sequentially down the

data table from 1 to 175.

Attribute Definition Source: None

Attribute Domain Values:

Range Domain:

Range Domain Minimum: 1

Range Domain Maximum: 175

Attribute:

Attribute Label: Sample_No

Attribute Definition: The Sample_No is the number or combination of numbers and letters that was

assigned to a sample when it was collected in the field, or shortly thereafter. The letters, if

present, indicate the initials of the person who collected the sample and the first two numbers

(if present) represent the last two digits of the year in which the sample was collected. After

the first two numbers (possibly with two letters, pattern may vary for some samples) is a dash

followed by a unique number that indicates a sample’s place in the order of collection for a

particular year. For example, the seventy-seventh sample collected by Stanley Mertzman in

2004 has the sample number 04SM-77.

Attribute Definition Source: None

Attribute Domain Values:

Unpresentable Domain: The values of this attribute were created systematically (mostly), but

they are not all numerical and there is no very easy way to describe the domain of

these values without creating a sizeable list of the actual values. It is best to

understand how the Sample_No attribute was assigned as discussed in the Attribute

Definition above.

Attribute:

Attribute Label: KAr_Age_Ma

Attribute Definition: The KAr_Age_Ma is a sample’s absolute age in millions of years as determined

by K-Ar or ⁴⁰Ar/³⁹Ar dating methods. Not all samples collected in the Mule Hill 7.5′

quadrangle have been age-dated; a total of 29 samples collected from outcrops (and two

from float material within landslide deposits) within this quadrangle have been age-dated.

Also provided is the error range of the dated age of a sample.

Attribute Definition Source: Consult Mertzman et al. (2008).

Attribute Domain Values:

Range Domain:

Range Domain Minimum: 1.79 +/- 0.12

Range Domain Maximum: 21.6 +/- 0.5

Attribute Units of Measure: Millions of years (Ma)

Attribute:

Attribute Label: Qtr_of_Qtr

Attribute Definition: The Qtr_of_Qtr attribute is the quarter-quarter section classifier of the Public

Land Survey System (PLSS). This attribute describes in what quarter (NW, NE, SE, SW)

of a quarter section of a section of a township a sample was collected. All Township

descriptors for samples collected within Oregon are according to the grid defined by the

Willamette Meridian and Willamette Base Line of the PLSS. Samples collected within

California are given Township descriptors according to the Mt. Diablo Meridian and Mt.

Diablo Base Line.

Attribute Definition Source: Consult

http://www-atlas.usgs.gov/articles/boundaries/a_plss.html

and http://www.blm.gov/or/landrecords/legaldescrip.php

Attribute Domain Values:

Enumerated Domain:

Enumerated Domain Value: NW

Enumerated Domain Value Definition: The northwest quarter of a quarter section of a

section of a township.

Enumerated Domain Value Definition Source: Consult

http://www-atlas.usgs.gov/articles/boundaries/a_plss.html

Enumerated Domain:

Enumerated Domain Value: NE

Enumerated Domain Value Definition: The northeast quarter of a quarter section of a

section of a township.

Enumerated Domain Value Definition Source: Consult

http://www-atlas.usgs.gov/articles/boundaries/a_plss.html

Enumerated Domain:

Enumerated Domain Value: SE

Enumerated Domain Value Definition: The southeast quarter of a quarter section of a

section of a township.

Enumerated Domain Value Definition Source: Consult

http://www-atlas.usgs.gov/articles/boundaries/a_plss.html

Enumerated Domain:

Enumerated Domain Value: SW

Enumerated Domain Value Definition: The southwest quarter of a quarter section of a

section of a township.

Enumerated Domain Value Definition Source: Consult

http://www-atlas.usgs.gov/articles/boundaries/a_plss.html

Attribute:

Attribute Label: Qtr_of_Sec

Attribute Definition: The Qtr_of_Sec attribute is the quarter section classifier of the (PLSS). This

attribute describes in what quarter section (NW, NE, SE, SW) of a section of a township a

sample was collected. All Township descriptors for samples collected within Oregon are

according to the grid defined by the Willamette Meridian and Willamette Base Line of the

PLSS. Samples collected within California are given Township descriptors according to the

Mt. Diablo Meridian and Mt. Diablo Base Line.

Attribute Definition Source: Consult http://www-atlas.usgs.gov/articles/boundaries/a_plss.html

and http://www.blm.gov/or/landrecords/legaldescrip.php

Attribute Domain Values:

Enumerated Domain:

Enumerated Domain Value: NW

Enumerated Domain Value Definition: The northwest quarter section of a section of a

township.

Enumerated Domain Value Definition Source: Consult

http://www-atlas.usgs.gov/articles/boundaries/a_plss.html

Enumerated Domain:

Enumerated Domain Value: NE

Enumerated Domain Value Definition: The northeast quarter section of a section of a

township.

Enumerated Domain Value Definition Source: Consult

http://www-atlas.usgs.gov/articles/boundaries/a_plss.html

Enumerated Domain:

Enumerated Domain Value: SE

Enumerated Domain Value Definition: The southeast quarter section of a section of a

township.

Enumerated Domain Value Definition Source: Consult

http://www-atlas.usgs.gov/articles/boundaries/a_plss.html

Enumerated Domain:

Enumerated Domain Value: SW

Enumerated Domain Value Definition: The southwest quarter section of a section of a

township.

Enumerated Domain Value Definition Source: Consult

http://www-atlas.usgs.gov/articles/boundaries/a_plss.html

Attribute:

Attribute Label: Sec

Attribute Definition: The Sec is the Section of the Township (according to the PLSS grid) in which

the sample was collected. The Section is “a one-square-mile block of land, containing 640

acres, or approximately one thirty-sixth of a township. Due to the curvature of the Earth,

sections may occasionally be slightly smaller than one square mile.” All Township descriptors

for samples collected within Oregon are according to the grid defined by the Willamette

Meridian and Willamette Base Line of the PLSS. Samples collected within California are

given Township descriptors according to the Mt. Diablo Meridian and Mt. Diablo Base Line.

Attribute Definition Source: Consult http://www-atlas.usgs.gov/articles/boundaries/a_plss.html

and http://www.blm.gov/or/landrecords/legaldescrip.php

Attribute Domain Values:

Range Domain:

Range Domain Minimum: 1

Range Domain Maximum: 36

Attribute:

Attribute Label: T_S

Attribute Definition: The T_S (Township_South) is the value of the horizontal row of townships in the

PLSS grid (Willamette Meridian and Willamette Base Line for samples collected in Oregon,

Mt. Diablo Meridian and Mt. Diablo Base Line for samples) in which the sample was

collected. The “S” (South) descriptor indicates that the township rows that pertain to this data

set are south of the Willamette Base Line of the PLSS (for samples collected within Oregon,

that is; samples calculated in California were actually collected north of the Mt. Diablo Base

Line). When combined with the R_E (Range) attribute value, this information provides the

specific ~36 square mile Township in the Willamette Meridian and Base Line defined grid of

the PLSS (Mt. Diablo Meridian and Base Line for samples collected in California) in which

the sample was collected. The other more specific PLSS descriptor attributes were described

and discussed above.

Attribute Definition Source: Consult http://www-atlas.usgs.gov/articles/boundaries/a_plss.html

and http://www.blm.gov/or/landrecords/legaldescrip.php

Attribute Domain Values:

Range Domain:

Range Domain Minimum: 40

Range Domain Maximum: 48

Attribute:

Attribute Label: R_E

Attribute Definition: The R_E (Range_East) is the value of the vertical column of townships in the

PLSS grid (Willamette Meridian and Willamette Base Line for samples collected in Oregon,

Mt. Diablo Meridian and Mt. Diablo Base Line for samples collected in California) in which

the sample was collected. The “E” (East) descriptor indicates that the township columns that

pertain to this data set are to the east of the Willamette Meridian (east of the Mt. Diablo

Meridian for samples collected in California, too). When combined with the T_S attribute

value, this information provides the specific ~36 square mile Township in the Willamette

Meridian and Base Line defined grid of the PLSS (Mt. Diablo Meridian and Base Line for

samples collected in California) in which the sample was collected. The other more specific

PLSS descriptor attributes were described above.

Attribute Definition Source: Consult http://www-atlas.usgs.gov/articles/boundaries/a_plss.html

and http://www.blm.gov/or/landrecords/legaldescrip.php

Attribute Domain Values:

Range Domain:

Range Domain Minimum: 3

Range Domain Maximum: 6

Attribute:

Attribute Label: UTM_E_m

Attribute Definition: This is the easting value in meters of a sample’s collection location according to

the NAD 1927 UTM Zone 10 projection system. This value was determined with the

MapInfo Professional version 7.0 Coordinate Extractor extension. In cases where the UTM

coordinates were already known, the coordinate extractor extracted these same coordinates.

Please note that the precision indicated by this value does not necessarily represent the

precision with which a sample’s location was determined. Instead, it represents the precision

of the MapInfo v.7.0 Coordinate Extractor extension’s results as determined for carefully

digitized sample location points (from original paper maps to the drg of the quadrangle,

except where coordinates were provided and already rounded to the nearest 10 meters).

Attribute Definition Source: Consult http://erg.usgs.gov/isb/pubs/factsheets/fs07701.html

Attribute Domain Values:

Range Domain:

Range Domain Minimum: 562,308.91

Range Domain Maximum: 572,417.69

Attribute Units of Measure: meters

Attribute:

Attribute Label: UTM_N_m

Attribute Definition: This is the northing value in meters of a sample’s collection location according to